clxxiv PROCEEDINGS OF THE KOYAL HORTICULTURAL SOCIETY. 
may be most readily distinguished by the microscopist who is not a 
specialist in worms is the number and arrangement of the setae. As in 
other oligochaets, there is an entire absence of setae, or bristles, on the 
first segment ; while on the twelfth segment, which bears the girdle or 
clitellum, and the male-pores, the ventral bundles are missing. All the 
other segments, of which there are thirty in an adult worm, bear four 
bundles of setae, of which two bundles are lateral and two ventral. In 
the first eighteen segments, or thereabouts, there are three setae in each 
ventral bundle, and two in each lateral ; but in the last ten or twelve 
segments each bundle, ventral and lateral alike, has three set^e. Thus 
the bundles are all either couples or triplets, and the order and arrange- 
ment are definite, not irregular or promiscuous. There is a large head- 
pore between the prostomium and the first ring, i.e. the one without 
set^e, and when a little pressure rests upon the worm's body, the fluid 
and particles contained within the coelomic cavity and head are poured 
out of this aperture, thus relieving the pressure. The brain is somewhat 
pear-shaped, rounded off, or convex at the hinder margin, and there is a 
slight tendency on the part of the ventral nerve- cord to broaden between 
the third and fourth segments. The blood-vessels and other parts are of 
10 15 
Fig. 182.— Aster-worm, Enchytr.i^us parvulus. (Gardeners' Chronicle.) 
the usual type : the girdle is slightly papillose, and accompanying the 
pores on the twelfth segment are somewhat large vase- shaped glands. 
" It will at once be seen that the worm comes very near to E. argenteus, 
Michaelsen, and it seems likely that the British and German forms may be 
ultimately referable to the same species. In that case the name ])arvu- 
lus will be withdrawn. 
" Curiously enough, though the fact has been more than once referred 
to since, our great authorities on this group of annehds make no allusion 
to the predatory life of the worms belonging to this genus or order. I 
have frequently examined white worms belonging to the Enchytraeidae, 
which were living on the roots of plants ; and have notes of more than 
one species new to science which were infesting grass crops, so that it 
may be regarded as a well-established fact that the white worms belong- 
ing to the genus E^ichytroius and its allies are destructive to plants. 
" My observations confirm those of Mr. Harker. The minute worm 
obtains admission to the roots and rootlets, and lodges under the epider- 
mis, where it sucks the juices of the plant, or even (as microscopic 
examination shows) breaks up its cell structure and swallows the vegetable 
tissues, thus preventing the plant from sending moisture and nutriment 
through the stem to the leaves. Though the worms have no teeth, their 
